Electric-switch box



(No Model.)

E. R. KNOWLES. ELEOTRIG SWITCH BOX.

No. 520,852. Patented June 5, 1894.

UNITED STATES PATENT OFFICE.

EDWARD R. KNOWVLES, OF MIDDLETOWN, CONNECTICUT, ASSIGNOR TO THE SCHUYLER ELECTRIC COMPANY, OF CONNECTICUT.

ELECTRIC-SWITCH BOX.

SPECIFICATION forming part of Letters Patent No. 520,852, dated June 5,1894.

Application filed December 5,1893. Serial lilo-492,862. (N0 model.)

To aZZ whom it may concern.-

Be it known that I, EDWARD R. KNowLns, a citizen of the United States, residing at Middletown, in the county of Middlesex and State of Connecticut, have invented certain new and useful Improvements in Water-Tight Electric-Switch Boxes, of which the following is a specification.

In certain electric installations it is necessary to carefully protect all the conductors, switches,&c., from wet and dampness. This is especially so in search lights, which are frequently exposed to all sorts of weather, and require very careful insulation and protection. My invention was designed especially for use with search lights, but it is useful in any situation where the switch contacts must be thoroughly protected.

Theinvention consists in a double pole snap switch inclosed in a water-tight box, and having an operating handle on the outside of the box.

In the drawings Figure 1 is a view of the under side of the cover, with its attached parts. Fig. 2 is a plan view of the switch box with the cover removed. Figs. 3, 4 and 5 are details.

The switch box A is rectangular, the bottom and sides being cast integral. Fastened to the bottom are four binding posts B B with set screws 1), to receive and hold the ends of the line conductors C, which enter the box through suitable screw threaded necks D provided with glands d and tapering elastic bushings d. Upon tightening the glands, the bushings are compressed around the conductors C so as to make a tightjoint. The binding posts are preferably located near the ends of the box, as shown, and each postB has an arm I) carrying a contact b preferably one or more elastic leaves, with which it can engage the contact arm b pivoted on an car 19 on the post B. The two contact arms 11 are mechanically connected by a link E of insulating material such as hard rubber, so that they are compelled to move simultaneously. The link has a pin e, which lies between the arms f f, of a forked block F, pivotally mounted on the cover A of the box by means of a short vertical shaft G journaled in a hole in the cover. On the outer end of the shaft fits the hub h of the handle II. The hub is loose, being connected with the shaft only by a pin g, which is fixed transversely in the shaft and projects at one or both ends into slots h in the hub of the handle. This affords a certain amount of lost motion between the handle and the shaft.

Along each side of the block F runs a slot, the two being parallel. They may be cut in the block, or they may be formed by rods f extending along the outer sides of recesses in the block and fixed at each end in the block. In each slot works an eye I which may have an anti-friction wheel 2', and is attached to one end of a strong helical spring K, the other end of which is secured to the cover A. The eyes tend to slip to the ends of the slots, and hold the blocks in one of two positions, as shown in Fig. 1. When the handle H is moved, the block is turned until the two springs have been somewhat stretched and the slots become so inclined that the eyes I are pulled suddenly by the springs to the opposite ends of the slots, which actioninstantly carries the block to its extreme opposite position. The lost motion in the handle permits the block to move without any hinderance. The arms f f are so far apart that they do not strike the pin 6 until the block is given its sudden pull, when the pin is struck and the arms b? are suddenly thrown out of or into contact with the leaves b The cover A is suitably fastened to the box A, and the joint is packed in any desired manner. It will be seen that there is no permanent connection between the block F and the link E, so that when the cover A is removed, the block, with its actuating handle and springs, is removed with it, leaving the contacts readily accessible, and avoiding the necessity of taking apart any of the mechanism to get the cover off.

Having thus described my invention, what I claim is- 1. A switch box, comprising a pair of contact arms connected by an insulating link, a block pivotally mounted on the under side of the box cover and having a fork to engage with said link, springs having one end secured to the cover and the other end attached to an eye sliding in a slot in said block, and a handle on the outside of the cover, adapted to operate said block through a lost motion device.

2. A water-tight switch, comprising the box A with its cover A and screw threaded necks D, the glands cl and taper bushings d, the binding posts 13 B, with arms I) and ears b the contact leaves b and pivoted contact arms 10 b the link E connecting said arms and having the pin e, the block F mounted on the shaft G journaled in the cover A, said block 

